1. Field
The following description relates to a Direct Current (DC) offset estimation, and more particularly, to a method and system for estimating and compensating for a DC offset in an Ultra-Low Power (ULP) receiver.
2. Description of Related Art
In general, a wireless receiver may include an analog front end. A Direct Current (DC) offset may be an important factor in an analog receiver including in the analog front end. The DC offset may arise from Local Oscillator (LO) leakage and component mismatching. The DC offset may be generated due to, for example, LO leakage self-mixing, transmission leakage self-mixing, and strong interference self-mixing.
The DC offset may be generated in an analog receiver front end in which the LO signal is mixed with an input Radio Frequency (RF) signal. The DC offset may need to be removed prior to baseband demodulation for a reliable communication. In an Ultra-Low Power (ULP) sliding Intermediate Frequency (IF) non-coherent receiver, the DC offset may cause degradation in a Packet Error Rate (PER) performance.
When gain of a baseband stage is high, a small magnitude of DC offset may also be get magnified due to the high gain and thus, the DC offset may need to be removed. If the DC offset is not removed, degradation in performance may occur in a receiver. Accordingly, there is a desire for a method of compensating for a DC offset in a ULP receiver.
There are provided various DC offset compensation methods. Alternating Current (AC) coupling and high pass filtering may be used as an efficient method of removing a time-invariant DC offset. Alternatively, a time-invariant DC offset in an in-phase arm and a quadrature arm may be calibrated, stored in a memory, and input to a subtraction circuit. A typical method of compensating for the DC offset may be performed through an individual processing for each of an in-phase component and a quadrature component in the receiver, which may use an additional hardware and increase time consumption.